This invention relates generally to devices and methods for capturing a topography of a three-dimensional (3D) object surface by sensing the physical surface arrangement and producing computer data representing that surface. More specifically, this invention relates to a 3D encoder and method of use.
The process of generating a 3D computer representation by sensing a surface configuration of a tangible 3D object is known as 3D object encoding. An encoding device is typically referred to as an encoder. Instrumented articulated arms are one type of conventional 3D encoders. These encoders have sensors for determining a spatial location of a pointer on an end of an articulated arm. In operation, the arm is positioned such that the pointer on the end of the arm contacts a 3D object at a sampling point along the object""s surface. Data from the arm""s sensors, indicating the location of the pointer, is sent to a computer. This sensor data is then translated by the computer into spatial (X, Y, and Z) coordinates of the 3D surface at the sampling point using complex computer software. The pointer is then moved to another point along the object surface and the coordinates corresponding to that point are obtained. This process is manually or automatically continued until a desired number of points along the surface of the object have been sampled.
After the desired number of points have been sampled, the X, Y, and Z coordinates from all of the sample points are combined using the computer software to create a 3D mapping of the object. The 3D mapping can be used to display a computerized image corresponding to the 3D object or to permit other desired use or manipulation of the data representing the 3D object. Although instrumented arm assemblies can produce a fairly accurate mapping, they require complex and expensive equipment and software and using them is difficult and time consuming.
A laser 3D encoder is another type of conventional 3D encoder. While laser 3D encoders are generally somewhat simpler to use than the instrumented articulated arm encoder described above, it is also generally more complex and expensive. When using a laser 3D encoder, a 3D object to be encoded is placed on a turntable of the device. A laser scans the surface of the object as the turntable rotates. Sensors detect the lasers as they are reflected from the object""s surface and provide data to a computer regarding the contours of the scanned surface. A complex computer program then converts the sensor data into a computerized representation (i.e., a 3D mapping) of the object""s surface.